单项选择题 The oil discharge monitoring system in the oil tanker vessels is used for detecting the amount of oil discharged overboard to ensure that it does not exceed（）

单项选择题 To receive oil residues from the purification of fuel and lubricating oils in the machinery spaces, what kind of tank(s) should be provided on board?（）

单项选择题 Which cause of following will not lead to refrigeration plant short-cycle?（）